8 May
The 1922 Committee of Conservative backbenchers will consider again whether to change the rules of the party to allow another confidence motion in Theresa May before December. Brexit supporters on the committee want a leadership contest to begin almost immediately to allow MPs to choose a shortlist before summer recess and for the party membership to vote on the final choice over the summer.
22 May
This is the final day on which MPs could pass a Brexit withdrawal deal to avoid holding European parliament elections, although ministers have now concluded this is highly unlikely.
23 May
European parliament elections take place across the UK and the rest of the EU, with any campaign likely to be dominated in the UK by smaller protest parties including Nigel Farage’s Brexit party and Ukip, as well as Change UK.
24 May
Experts suggest this is roughly the point at which May would have to announce a second referendum if all necessary legislation were to be passed to hold a poll before the new Brexit deadline of 31 October. However, in practice, a referendum could be announced at any time and an extension secured from the EU to allow it to happen.
26 May
Results of the European elections are declared from 10pm, with the Conservatives expecting massive losses. From the limited amount of polling that has been carried out so far, the Brexit party or Labour look like the probable winners.
27 May
If May has not already announced a date for her departure, the 1922 Committee may decide this is the point at which it tries to force her out through a rule change. It would allow for a month-long contest among MPs before summer recess.
The 1922 Committee is the shorthand name for the parliamentary group of backbench Conservative MPs that meets weekly while parliament is in session.
The group has an executive body of 18 backbench MPs who oversee the organisation of Conservative party leadership elections. Under their current rules Theresa May cannot face a leadership challenge until December 2019, having survived a vote of no confidence last year.
The name derives from it being formed originally by a small group of MPs who were elected for the first time in the 1922 general election, before expanding to become the main representative group of Conservative MPs who are not part of the government itself.
15 June
Grassroots activists will attend an emergency meeting of the National Conservative Convention, the most senior body of the party’s voluntary wing, to debate a confidence motion in the prime minister. It will not be binding but a defeat would be hugely embarrassing for May and increase pressure on her to resign.
30 June
This is the crucial date past which May said she would not countenance the UK staying in the EU. May must have passed her withdrawal deal before this date in order avoid British MEPs taking up their seats. This is another moment at which Tory MPs could attempt to move against the prime minister, if she has failed to pass her deal and ignored a no-confidence motion by grassroots activists.
25 July
With the Commons expected to begin summer recess, this is the date by which the party would, ideally, like MPs to have drawn up a shortlist of two leadership candidates for members to vote on over the holiday period. If May remains in post with no challenge, the issue is likely to drift over the recess with no more movement until September.
Mid-August
This is the approximate time by which May or her successor as leader would need to call a general election for it to be held before the article 50 extension expires. This is not a likely option as a new prime minister would need time to bed in and formulate their Brexit strategy, and Conservative MPs would not let May lead them into another contest.
5-12 September
The Commons is expected to return from summer recess, bar any early recall to deal with a Brexit crisis. If May has not announced a leadership contest and is still trying to pass her deal, she may get one last shot at this. Otherwise, she will have to come up with another plan or finally announce a contest to allow someone else to rethink strategy.
22 September – 2 October
The Labour and Conservative party conferences are held on consecutive weeks. It is possible that a new Tory leader could be unveiled at this contest after a summer of voting by party members. Alternatively, it could be used to showcase the wide array of candidates who are putting themselves forward for MPs to whittle them down to a shortlist of two. If May remains prime minister with no hint of a timetable for her resignation, grassroots activists at the conference are likely to give her a furious reception.
8 October
MPs return to parliament, 18 working days before the UK would be due to leave the EU. If no new leader is yet in place, and the prime minister has failed to pass her deal, it would be looking likely that the UK would have to request a further extension.
10 October
This is the last practical polling date on which a prime minister could hold a general election or second referendum – the final Thursday before the next meeting of the European council.
The Electoral commission is suggesting it would need 10 weeks to organise a poll, as set out in the Political Parties, Elections and Referendums Act 2000, and that there would be a campaign of at least four weeks.
In practice, a change of policy or government this late in the timetable would be likely to require a further extension if a radical change of direction is expected.
17-18 October
EU leaders meet for the final meeting of the European council before the UK’s extension is due to expire. It is another point that Tory MPs could try to move against the prime minister if she put forward another request for an extension without accepting the pressure for her to let a colleague take over.
31 October
The six-month article 50 extension will expire.
12 December
The next date on which Tory MPs can hold a confidence vote in May, if she remains at the helm.
